In radiated performance test of a wireless terminal, radiation signals and receiver sensitivities in a plurality of directions should be measured, and a total radiated power (TRP for short) and a total isotropic sensitivity (TIS for short) are obtained by mathematical calculation based on the measured data. Since an antenna of a mobile wireless communication terminal is usually not directional, but radiates to all directions of space, when testing wireless performance of the mobile terminal, a basic idea is to put a device under test at a center of a sphere, measure signal strengths at a plurality of positions on surface of the sphere by test antennas, and calculate a total radiated intensity after obtaining measured values of all positions.
At present, according to a test standard of CTIA (Cellular Telecommunications Industry Association), a great circle test method is used mainly. A mobile terminal under test is put on a center of a three dimensional turntable, and may rotate around two axes with the turntable. By using one test antenna and setting both the mobile terminal and the test antenna in an anechoic chamber, the direct signal emitted to the test antenna by the mobile terminal under test is received by the test antenna, and the radiation signals emitted to other directions by the mobile terminal are absorbed by absorbing material set in the anechoic chamber. When testing, the mobile terminal is rotated with a preset angle interval according to a test demand. The mobile terminal is stopped to measure the signal strength when rotated to each position. A test duration may be reduced by adjusting the angle interval. After the radiation signals in all directions are tested, a test result is generated by integration and other data processing accordingly.
However, a test speed of this system is low, and it is needed that a distance between the test antenna and the device under test to be larger than a far field distance, thus causing a huge volume, a high manufacturing cost, and a small application scope of the test system.